Apparatus for roasting and drying ores



4 Sheets-Sheet 1.

P. ARGALL.

APPARATUS PoR RoAsTING AND DRYING oRBs.

(No Model.)

No. 591,909. Patented Oct. 19,1897.`

@woe/whoa (No Model.) l 4 Sheets- Sheet 2. P. ARGALL.

APPARATUS POB. ROASTING AND DRYING GRES. No. 591,909. Patented Oct.19,1897.

'(No Model.) 4 Sheets-Sheet 3.

^ P. ARGALL.

APPARATUS FOR ROASTING AND DRYING DRES.

No. 591,909. Patented Oct. 19,1897.

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P. ARGALL. APPARATUS FOR ROASTING AND DRYING GRES.

No. 591,909. Patented Oct. 19,1897.

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I INITED STATES PATENT rErcE.

PHILIP ARGALL, OF DENVER, COLORADO.

APPARATUS FOR ROASTING AND DRYING ORES.

SPECIFICATION forming part Of Letters Patent No. 591,909, dated October19, 1897.

Application filed February 4,1896. Serial No. 577,966. (No model.)

To @ZZ whom it may concern.'

Be it known that I, PHILIP ARGALL, a citizen of the United States,residing at Denver, in the county of Arapahoe and State of Colorado,have invented a certain new and useful Improvement in Apparatus forRoasting and Drying Ores, of which the following is a speci- 'iicatiornreference being had therein to the accompanying drawings.

The invention relates to a rotatable tubular furnace for drying orespreparatory to crushing the same for the cyanid, chlorination, or otherprocess where the ores must be crushed in a dry state.

The invention is also used for roasting the dried and pulverized' ore orfor the general roasting or calcination of ne ores or furnace products.l

The objection to the rotatable furnaces heretofore in use for roastingores is that on account of the great diameter of the furnaces the iiameand gases are not brought in intimate contact with the ore. The ore isnot thoroughly oxidized because of its insufficient contact or admixturewith the air, and, furthermore, the cylinder in such furnaces is alwaysout of balance while being rotated,which necessitates the employment ofgreat and expensive motive power. Again, the loss in dust is heavy,as'the draft carries off large quantities of the fine ore or dust.

The object of my invention is to overcome all these difficulties andprovide an apparatus whereby the ore to be treated may be rapidly andperfectly oxidized, the loss of fine ore or dust reduced to a minimum,with the use of but little motive power.

The invention consistsin the novel features of construction of thetubular furnace hereinafter set forth and described, and moreparticularly pointed out in the claims hereto appended.

Referring to the drawings, Figures l and 1' represent together alongitudinal section of the entire furnace, a portion of which is takenon the lines 1 l of Figs. 2 and 3. Fig. 2 is a view of a transversesection taken on the line 2 2 of Fig. l, showing the parts beyond thesectional plane in elevation. Fig. 3 is a sectional view taken on theline 3 3 of Fig. la. Fig. 4 is a view of a transverse section of therabble, taken on the line et 4 of Fig. 5. Fig.

5 is a side elevation of the rabble, partly in section, said sectionbeing taken on the line 5 5 of Fig. 4. Fig. 6 isa plan view of therabble, partially broken away.

Like letters refer to like parts throughout the several views.

af, c2, c3, and a4 denote the tubes of the furnace. They are rmlyrivetedtogether at the point of contact and also to the cast-iron center piecesb b, and they are securely attached to the cast-iron rings ortrack-bands c c', to form, as it were, one tube or a series of tubeswhich rotate as one tube. These tubes are lined with lire-clay circles dto retain the heat, and are made preferably of steel-plate to make themlight in weight. I find in practice that twenty to twenty-six inches isthe most suitable inside diameter for these tubes when used for.roasting ores and that the most suitable length is twenty-five to thirtyfeet for roasting and fifteen to twenty feet when the tubes are employedfor drying ores, although I do not hereby intend to limit the inventionto tubes of these exact dimensions, nor to limit myself to the use offour tubes, for it is obvious that the dimensions of the tubes may bevaried and that more than this number of tubes may be used withoutdeparting from the spirit of my invention.

e denotes the smoke-chamber, f the hopper, and g the chute throughwhichthe ore is fed into the furnace. At the feed end of the furnace thevtubes Vare joined into one large tube h, which is also lined withfire-clay circles d. This tube h is in the nature of a cap or hood,which fits over and is secured to the ends of the tubes, and at the sametime iills up the interstices between the pipes, so that the ore may beproperly fed to the tubes.

At the discharge end of the furnace the tubes are preferably joined intoone large tube Vz', similar in construction to the large tube h, so thatthe iiame from the furnace k, which in the drawings is arranged for oilfuel, may readily pass into the tubes.

To supply hot air for drying or oxidizing the ore, one or more fixedhollow rabbles Z are used in each tube. These rabbles are preferablymade in one casting, closed at both ends and secured to the inside ofthe tube by means of the bolts Z. The air is circulated throughitheserabbles bymeans of a fan or IOO other suitable means. The air passesthrough the supply-pipe m, thence into the air-box n and through thedistributing-pipes n', n2, n3,

and n4 into the tube Z2, and having traversed the full length of thetube Z2 passes into the tube Z3 at the fire end of the furnace andemerges through the holes Z4. Over the row of holes Z4 I have shown aprojecting ledge or flange, which not only aids in the properdistribution of the ore during aeration, but also protects the outletair-passages and prevents them from bein g clogged by the shifting massof ore. The pipe m revolves in the sleeve m and rotates, together withthe connections between itself and the rabbles, with the furnace-tubes.

o o' and o2 o3 denote two pairs of carryingwheels, the track-band cresting upon the wheels 0 0, and the track-band c' resting upon thewheels o2 o3. The carrying-wheels are mounted upon suitable bearings,which in turn are mounted upon suitable base-blocks or standards.

The furnace is revolved by means of power transmitted to thecarryingwheels 0 02, through the drive-chainp, the sprocket-wheel p',the intermeshing cog-wheels 292193, and the shaft p4, to which thecarrying-wheels ol and o2 are rigidly secured.

q is a revolving thrust-bearing mounted upon suitable bearings in theblock q', which is securely bolted to the base-blocks or standards.

The capacity of the furnace can be increased or diminished by changingthe speed of its revolution or by changing the angle of its inelination.

The under sides of the blocks q2 q2 are provided with a male plate r,adapted to lit into a female plate r on the blocks Q3 g3, thus forming arocking bearing, which permits the tilting of the furnace and themechanism for revolving the same without the liability of disarrangingthe parts.

8 and sare cast-iron frames fastened to the side of the smoke-chamber,and tt' are aprons, elliptical in form, fastened to said framesrespectively and extending nearly to and around a portion of the tube h.

s2 and s3 are cast-iron frames fastened to the sides of the furnace 7c,and t2 and 253 are aprons, elliptical in shape, fastened to said framesrespectively and extending nearly to and around a portion of the tubet'.

When it is desired to increase or diminish the angle of inclination ofthe tubes, the base-blocks under and near the feed end of the furnaceare raised or lowered and the aprons t, t', 252, and t3 raised orlowered, as the case may be.

justed by jack-screws or any suitable means well known to those skilledin the art, to which I lay no claim. It is to be observed that thefurnace is always perfectly balanced, no matter what position the tubesare in, as may be seen from examination of Fig. 3, in

The said angle of inclination is adwhich u represents the ore. Thefurnace, therefore, requires but little motive power to revolve it,thereby causing a considerable economy. Owing to the small diameter ofthe tubes, a very great difference in temperature can be obtainedbetween the fire end and the feed end-that is, the re' end can be keptred-hot while the feed end will remain comparatively cool, the heatbeing absorbed by the ore and moisture when the furnace is used fordrying ores, whereas in a singletube furnace the flame would rushlthrough and heat the cylinder up nearly as hot at the y The operation ofthe furnace in roasting ore,

in so far as it has not already been described, is as follows: As thefurnace revolves the raw ore is fed into the large tube 7L and graduallypasses into the small tubes to', co2, a3, and CL4, and thence along themto the discharge end. The small tubes bring the fiame and gases inintimate contact with the ore, while the hollow rabbles at the sainetime pass through the charge and eject pure hot air, uncontaminated bythe products of combustion, directly into and through the entire mass ofore as the furnace revolves, thus oxidizing and completing the roastingin the most rapid and perfect manner. In drying ores the furnace isoperated in a similar manner, except that the ore to be operated uponwould be much coarser and the temperature employed would be much lower.I-Iere also the hot air ejected into the body of the oreV as the furnaceis revolved rapidly carries oi the moisture and dries the ore moreeffectually than if it were subjected alone to the action of the iiameand gases of combustion passing over it.

What I claim, and desire to secure by Letters Patent, is-

l. In a roasting or drying furnace, the combination of a plurality ofindependent noncommunicating cylindrical tubes symmet rically arrangedaround a common axis, mounted in an inclined position and so as to IOOIIC

be rotated as one, with a combustion-chamj ber sending its products ofcombustion through all the tubes at once, when all are charged with thematerial to be operated upon in balanced charges, in conjunction withmeans provided in each tube for sending pure, hot, dry air through thesaid charges of ore during rotation, substantially as specied.

2. In a roasting or drying furnace, a revoluble cylinder or tube incombination with a. hollow rabble xed relatively thereto to the interiorthereof, and means for supplying air in conjunction with the said rabbleto the charge during the process of roasting or drying, substantiallyas'specified.

3. In a roasting or drying furnace, a revoluble cylinder or tube incombination with a hollow rabble comprising an air-tube having adjacentcommunicating direct and return flues vwith air-outlet passages leadinginto the said cylinder, said rabble being fixed relatively to the saidrevoluble tube to the interior thereof, and means for supplying air tothe said rabble during the process of roasting, substantially asspecified.

4. In a roasting and drying furnace, a revoluble cylinder or tube incombination with a hollow rabble fixed relatively thereto to theinterior thereof; said rabble comprising an air tube having adjacentcommunicating direct and return fiues with air-outlet passages leadinginto the said cylinder, means for preventing the air-passages frombecoming clogged, and means for supplying air to the said rabble, whilethe cylinder is revolving, substantially as specified.

5. In a roasting or drying furnace, a revoluble cylinder or tube incombination with a hollow rabble fixed relatively thereto, the saidrabble comprising an air-tube having air-outlet passages leading intothe said revoluble tube and provided with a projecting ledge or flange,whereby the air-,passages are prevented from becoming clogged, and means'for supplying air to the said rabble, substantially as specified.

6. In a furnace for roasting and drying ores, the multiple revolublegroup of independent cylinders terminating in a single large tube orhood at the feed end of the apparatus, and terminating also in a singletube at the discharge end, in combination with means for revolving saidcylinders, means for sending heated gases simultaneously through thesame while in revolution, means for feeding ore to the same, and meansfor sending pure, hot, dry air through the said ore while beingsimultaneously agitated and heated, substantially as specified.

7. In afurnace for roasting and drying ores, a multiple revoluble groupof cylinders provided both at the feed end and at the disthe multiplehollow revoluble group of tubes or cylinders c', a2, a3, a4 incombination with the hollow rabbles Z, iixed relatively thereto one ineach tube, having return-passages and outlet-perforations, and means forsupplying air in 'conjunction with said rabbles to the ore during theprocess of drying or roasting, substantially as specified.

9. In a furnace for roasting and drying ores, f v

the multiple hollow revoluble group of tubes or cylinders co', a2, co3,d4 in combination with hollow rabbles Z, one in each tube, fixed to theinside thereof, closed at both ends, having passages Z2, Z3, andperforations Z4, the supply-pipe m, air-box n, distributing-pipes n',n2, n3 and n4, and means for supplying air through the supply-pipe m andthe distributing-pipes While the furnace is in operation, substantiallyas specified.

l0. The combination of a multitubular revoluble cylinder, having asingle terminal tube or extension at each end, hollow rabbles, locatedone in each tube, fixed to the inside thereof, having direct and returnpassages, and outlet-perforations, means for revolving the saidcylinder, means for sending heated products of combustion through allthe tubes simultaneously duringrotation, and means for supplying airthrough the said rabbles and their outlet-perforations to the ore duringits agitation while being revolved and heated, all substantially as andfor the purpose specified.

In witness whereof I have hereto aiiixed my signature, this 15th day ofJanuary, 1896, in

the presence of two witnesses.

PHILIP ARGALL. Witnesses:

E. W. J ENKs, R. H. REID.-

